This project will study the structure, function, synthesis and insertion of several membrane proteins involved in transport processes in E. coli. Both biochemical and genetic approaches are employed to study constituents of each of the three sections of the bacterial envelope, with special emphasis on the use of the gene amplification provided following the induction of specialized transducing phages carrying the structural genes for these membrane proteins. Several of the transport systems to be studied and the features that they present include: 1 - Vitamin B12 transport, which uses a receptor on the outer membrane that also functions as a receptor for phage BF23 and the E colicins. The role of membrane adhesion sites and the possibility of the coupled insertion of proteins is of interest. 2 - Methionine transport, in which the nature and role of a periplasmic binding protein and the mechanism of energy coupling will be studied. The energy coupling in this system appears to be different from the previously described mechanisms. 3 - Lactose and other permeases, in which the gene amplification technique is employed to facilitate the identification and isolation of specific membrane proteins. The insertion of these proteins into artificial membrane systems will be attempted.